Power-hammer



A. T. LOCHNER.

POWER HAMMER.

APPLICATION FILED DEC. 26, 191B.

Patented Oct. 19, 1920 CQZY6J565" To all whom it my camera.-

UNITED ST -res PATENT OFFICE. v

ALBERT momsriocnnnn, or CHICAGO, ILLINOIS, ASSIGNOB T WODACK ELECTRIC TOOL conroaa'rron, or. CHICAGO, ILLINOIS,- a CORPORATION or ILLINOIS.

1 rowrm naimnn Be t known that I, ALBERT T110111? LooHNEn, a citizen of the United; States, .rej

siding. at Chicago, in the county ofvCoo k and- State of Ill nois, have invented certain new and useful Improvements in Power- Hammers, of which the following is 'a speci l fication. 1

parts is such as to The invention relates to power hammers and has forone of its objects the provision of a hammer of a very practicalcharacter wherein the relative arrangement of-fthe make the tool convenient inoperation.

, A further objectof the invention is to provide spring means advantageously arranged relative to the plunger-actuating mechanism for cushioningthe plunger when the tool is not ap lied to the work. p

The objects of t einvention thus generally stated, together with other and ancillary advantages, are attained by the con- 'struction' and arrangement illustrated in the accompanyingdrawings forming part hereof, in which Figure 1 is-a fragmentary.

"elevation-section ofa power hammer embodying the features of myinvention. 'Fig.

2 is a transverse section .on line 2-2 of Fig. 1-. Fig. 3 is a fragmentary'longitudr nal sectional view showing details of construction.

The hammer comprises, in general, a

body 1, a plunger 2, reciprocable in the body by actuating mechanism 3, and amotor 4 for driving the plunger-actuating mechanism? The body 1 comprises a" tubular member; 5 within which the plunger 2 isslidable and which is threaded onto the forward end of a tubular extension 6 of asubstantially cylindrical casing 7 I which /incloses the actuating mechanism 3. :Said tubular member 5\ and extension 6 form-the v I bearing stem 20 thereon which extends forjhammer barrel.

ably made up of, separate sections, consisting, for example, of-a-forward section 7 and a rear section 7 secured together ,by, 7 means of bolts 8 with an intermediate sec-y tion or spacing ring 9 entered therebetween to accommodate parts" of the 0 erating mechanism to be later described. erein a plate 10 is shown'as forming a bearing for the forward end of the motor spindle 11,

the rear secti n 7", of the cas g, and

Specification/of Letters Patent.

a tool 'a.

Paten'tedOct, 19, 1920.

Application filedDeoeniber 26, 1918. Serial No. 268,305.

9 being provided at. their adjacent edges withan interior annular groove to receive the perlpheral edges of the plate 10 and thereby hold. it in position. At the forward end of the body a tool holding sleeve 12 is secured within the tubular member 5, and at its rear end the body has a handle 13 suitably secured to the rear casing section7. a

The plunger 2 is mounted on the forward end of a rod 14 slidablein a bearing block 15 fixed in the tubular extension 6; and on the rear end of said rod is fixed a head 16. A cam disk 17, located between said head and the forward end of the casing 7, is operatively connected with the motor for rotation thereby and is provided with one or more cam surfaces 17 with which an arm'16' on the 'head (Fig. 2) is arranged to'slidably engage; It will be seen that as the cam disk is rotated, the cam surfaces 17* cooperate with the arm 16 to move the plunger' 2 rearwardly. This movement takes place against the action of a coiled spring 18 surrounding the rod 14 and bearing between the plunger 2 and the'bearing block 15, and it will be apparent that whenthe arm 16 rides off from a -cam surface 17 thespring 18 will impel the plunger for wardly to strike a blow upon the shank of Preferably the plunger rod 14 is made square, as shown v the opening through the" bearing block 15 being similarly shaped in order that the rod will be effectively held with a central opening'19 somewhat larger than the thickness of the rod so 'as to enable the rear end thereof to pass freely through i the opening. In order to provide 'an efficient mounting for thecam disk; independ- I ent' of the rod 14, I have provided'a tubular wardly'into a bore or socket 15 in the foragainst rotation. The disk 17 is provided The means by which the cam disk is .op-

.eratively connected to the motor for rotation thereby comprises a spur pinion 22'fix ed on the forward end of the motor spindle 11 and meshing with a spur gear 23 fixed on the rear end of a tubular stem 24;. Said stem is mounted on a shaft 25, the opposite ends of Whichmay be suitably mounted in the forward wall of the casing? and in the I bearing plate 10, respectively, and the forward end of the stem is provided with gear teeth 24* so as to mesh with gear teeth 26 provided on the periphery of the cam disk. It will be observed that the arrangement of the gearing connections as a whole is such that the hammer barrel may be offset toward the periphery of the casing 7, which renders the hammer readily adaptable to use in corners and similarly restricted places, thus increasing the convenience of the hammer in operation.

When the motor is operated a rapid reciprocation of the plunger 2 is effected by means ofthe actuating mechanism operatively connected with the motor in the manner just described, and the plunger in such reciprocation is adapted to act upon the shank of the tool a when the latter is applied to the work. When, however, the tool a is not applied to the work and theplunger is running idly, the impact of-the blow is received by acoiled spring 27 (Fig. 3) so that the wear and tear upon the parts which would otherwise result is substantially eliminated. I have arranged said spring 27 in is made of such length that it will afl'ect the operation of the plunger only when the tool is not applied to the work.

For the purpose of minimizing friction between the cam disk and the arm 16", a

roller 29 may, if desired, be mounted in the arm.

I claim as my invention: 1. A power hammer having, in combination, a plunger, spring means tending to moye the plunger in' one direction, means for moving the plunger in the opposite direction including a rotatable cam vdisk and a head adapted to cooperate therewith, a rod having said plunger-fixed on one end and said head fixed on the other end, and a coiled cushioning spring between said disk and head and surrounding the rod, said disk having a socket in its face adjacent the head for receiving said spring.

2. Apower hammer having, in combination, a body, a plunger, an operating member for the plunger, a rotatable cam member having a tubular stem 'journaled in the body coaxially of'the plunger, said operating member being adapted to operatively en gage with said cam member'to be moved thereby in one direction, a spring tending to move the plunger in the opposite direction, and a cushioning spring interposed'between said operating member and said cam member.

3. A power hammer having, in combina-- tion, a body, a plunger, a rod having said plunger fixed on one end, a bearingmember through which said rod is slidable, a r0- tatable cam member-having a tubular stem journaled in said bearing member, said rod extending through said cam member and its stem and having a head thereon adapted to cooperate with the cam member to move the plunger in one direction, and spring means tending to move the plunger in the opposite direction. Y r

4. In a power hammer having a plunger, mechanism for imparting movement to the plunger including a rotatable cam member and a non-rotatable member operatively associated 'therewith to impart movement to the plunger, and a spring interposed between said members.

In testimony whereof, I have hereunto set my hand. I

ALBERT THOMAS LOCHNER. 

